Direct cross-coupling method of benzyl sulfonium salt and thiosulfonate

Abstract

The invention discloses a direct cross-coupling method of benzyl sulfonium salt and thiosulfonate, and belongs to the technical field of organic compound synthesis. The benzyl sulfonium salt and the sulfo-sulfonate react in the solvent under the action of the metal, and sulfonium alkane products with various structures are obtained at medium to good yield. According to the reaction, the benzyl sulfonium salt easy to synthesize is used as a coupling substrate, thiosulfonate is used as a substitute of mercaptan, risks such as stink in the operation process are avoided, meanwhile, the benzyl sulfonium salt can be stored at room temperature, shows excellent thermodynamic stability, and is very safe and easy to prepare compared with other electrophilic reagents. The preparation method disclosed by the invention has the characteristics of mild reaction conditions, simple post-treatment, green steps, low pollution, high economic benefits and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of organic compound synthesis, and specifically relates to a direct cross-coupling method of a benzyl sulfonium salt and a thiosulfonate. Background Art

[0002] Direct coupling between electrophiles without transition metal catalysis has attracted wide attention in the synthesis community, because most transition metal catalysts and ligands are expensive and environmentally unfriendly. Thiosulfonates are a new type of organosulfur reagents used in the synthesis of CS bonds and have been proven to be versatile electrophiles that can synthesize CS bonds with substrates containing various directing groups to construct the corresponding target products. However, the direct coupling of benzylsulfonium salts, which are easy to prepare, stable in nature, and safe to operate, with thiosulfonates has not been developed so far. Summary of the invention

[0003] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0004] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0005] One of the purposes of the present invention is to provide a direct cross-coupling method of benzyl sulfonium salt and thiosulfonate, which has mild reaction conditions, simple post-treatment, green steps, low pollution, high economic benefits and the like.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a direct cross-coupling method of a benzyl sulfonium salt and a thiosulfonate, wherein the benzyl sulfonium salt shown in formula I and the thiosulfonate shown in formula II are reacted in a solvent under the action of a metal to obtain a compound shown in formula III;

[0007]

[0008] wherein Ar comprises one of a phenyl substituent, a 4-methylphenyl substituent, a 2,4,6-trimethylphenyl substituent, a 4-tert-butylphenyl substituent, a 3,4,5-trimethoxyphenyl substituent, a 4-methoxyphenyl substituent, a 1,3-benzodioxolyl substituent, a 4-trifluoromethylphenyl substituent, a 4-trifluoromethoxyphenyl substituent, a 4-formylphenyl substituent, a 4-cyanophenyl substituent, a 4-fluorophenyl substituent, a 4-phenylphenyl substituent, and a 2-naphthyl substituent;

[0009] R includes one of a phenyl substituent, a p-methylbenzene substituent, a p-tert-butylbenzene substituent, a p-methoxybenzene substituent, a p-(trifluoromethyl)benzene substituent, a 4-fluorophenyl substituent, a 4-chlorophenyl substituent, a 2-pyridine substituent, a 2-methylfuranyl group, a benzothiazole substituent, a 2-naphthyl substituent, and a benzyl substituent.

[0010] As a preferred embodiment of the direct cross-coupling method of benzyl sulfonium salt and thiosulfonic acid eye of the present invention, wherein: the benzyl sulfonium salt is selected from dimethyl benzyl sulfonium trifluoromethanesulfonate, dimethyl (4-methylbenzyl) sulfonium trifluoromethanesulfonate, dimethyl (2,4,6-trimethylbenzyl) sulfonium trifluoromethanesulfonate, (4-(tert-butyl)benzyl) dimethyl sulfonium trifluoromethanesulfonate, dimethyl (3,4,5-trimethoxybenzyl) sulfonium trifluoromethanesulfonate, dimethyl (4-methoxybenzyl) sulfonium trifluoromethanesulfonate, dimethyl (benzo [d] [1,3] di The invention can be selected from the group consisting of dimethyl (4-(trifluoromethyl)benzyl)sulfonium trifluoromethanesulfonate, dimethyl (4-(trifluoromethoxy)benzyl)sulfonium trifluoromethanesulfonate, dimethyl (4-(methoxycarbonyl)benzyl)sulfonium trifluoromethanesulfonate, dimethyl (4-(cyano)benzyl)sulfonium trifluoromethanesulfonate, dimethyl (4-(fluorobenzyl)sulfonium trifluoromethanesulfonate, dimethyl ([1,1'-biphenyl]-4-ylmethyl)sulfonium trifluoromethanesulfonate, and dimethyl (naphthalen-2-ylmethyl)sulfonium trifluoromethanesulfonate.

[0011] As a preferred embodiment of the direct cross-coupling method of benzyl sulfonium salt and thiosulfonate of the present invention, the thiosulfonate is selected from one of S-phenylbenzenesulfonylthioate, S-(p-tolyl)benzenesulfonyl sulfate, S-(4-(tert-butyl)phenyl)benzenesulfonylthioester, S-(4-methoxyphenyl)benzenesulfonylthioester, S-(4-(trifluoromethyl)phenylbenzenesulfonyl sulfate, S-(4-fluorophenyl)benzenesulfonylthioester, S-(4-chlorophenyl)benzenesulfonylthioester, S-(pyridin-2-yl)benzenesulfonylthioester, S-(2-methylfuran-3-yl)benzenesulfonylmethylsulfate, S-(benzo[d]thiazol-2-yl)benzenesulfonylthioester, S-(naphthalene-2-yl)benzenesulfonyl sulfate and S-benzylbenzenesulfonyl sulfate.

[0012] As a preferred embodiment of the direct cross-coupling method of benzyl sulfonium salt and thiosulfonate of the present invention, the molar ratio of the benzyl sulfonium salt to the thiosulfonate is preferably 1:2.

[0013] As a preferred embodiment of the direct cross-coupling method of benzyl sulfonium salt and thiosulfonate of the present invention, the metal is selected from one of manganese, iron, copper, aluminum, bismuth, indium, magnesium, tin, lead and zinc, and the preferred molar ratio of the metal to the benzyl sulfonium salt is 2:1.

[0014] As a preferred embodiment of the direct cross-coupling method of benzyl sulfonium salt and thiosulfonate of the present invention, the solvent is selected from tetrahydrofuran, dimethyl sulfoxide, N-methylpyrrolidone, 1,4-dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, acetonitrile, toluene and water, and the preferred solvent is N,N-dimethylformamide.

[0015] As a preferred embodiment of the direct cross-coupling method of benzyl sulfonium salt and thiosulfonate of the present invention, the reaction temperature is 25-50°C, preferably 50°C.

[0016] As a preferred embodiment of the direct cross-coupling method of benzyl sulfonium salt and thiosulfonate of the present invention, the reaction time is 6 to 12 hours, preferably 12 hours.

[0017] In summary, the chemical equation for the optimal reaction conditions of the present invention is as follows:

[0018]

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention provides a new method for direct cross-coupling of benzyl sulfonium salt and thiosulfonate, which not only uses benzyl sulfonium salt that is easy to synthesize as a coupling substrate, but also uses thiosulfonate as a substitute for thiol compounds, avoiding the dangers of odor and the like during the operation, and benzyl sulfonium salt can be stored at room temperature, showing excellent thermodynamic stability, and compared with other electrophilic reagents, they are also very safe and easy to prepare. The preparation method of the present invention has mild reaction conditions, simple post-processing, green steps, low pollution, high economic benefits, and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0022] Figure 1 This is the hydrogen spectrum of the target product benzyl(phenyl)sulfane of Example 1 of the present invention;

[0023] Figure 2 This is the carbon spectrum of the target product benzyl(phenyl)sulfane of Example 1 of the present invention.

[0024] Figure 3 This is the hydrogen spectrum of the target product (4-methylbenzyl)(phenyl)sulfane of Example 2 of the present invention;

[0025] Figure 4 This is the carbon spectrum of the target product (4-methylbenzyl)(phenyl)sulfane of Example 2 of the present invention.

[0026] Figure 5 This is the hydrogen spectrum of the target product benzyl(4-(tert-butyl)phenyl)sulfane of Example 3 of the present invention;

[0027] Figure 6 This is the carbon spectrum of the target product benzyl (4-(tert-butyl)phenyl)sulfane of Example 3 of the present invention. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0031] The raw material benzyl sulfonium salt (Formula I) used in the examples of the present invention was synthesized with reference to the following literature:

[0032] [1]Wang, W.; Yao, K.; Wu, F. Nickel-Catalyzed Reductive Cross-Coupling of Benzylic Sulfonium Salts with Aryl Iodides. Synlett2022,33,361-366.

[0033] The raw material thiosulfonate (Formula II) used in the examples of the present invention was synthesized with reference to the following literature:

[0034] [2] Moura, IMR; Tranquilino, A.; Sátiro, BG; Silva, RO; de Oliveira-Silva, D.; Oliveira, RA; Menezes, PH Unusual Application for Phosphonium Salts and Phosphoranes: Synthesis of Chalcogenides.

[0035] Unless otherwise specified, other raw materials used in the examples were purchased commercially.

[0036] Example 1

[0037] (1) Place the sealed tube equipped with a magnetic stirrer in an oven and dry for one hour. Take it out and plug it with a rubber stopper while it is still hot and insert a nitrogen balloon.

[0038] (2) After the mixture cooled to room temperature, dimethylbenzylsulfonium trifluoromethanesulfonate (151.2 mg, 0.5 mmol, 1 equiv.), S-phenylbenzenesulfonylthioate (250.3 mg, 1 mmol, 2 equiv.), and zinc powder (65.4 mg, 1 mmol, 2 equiv.) were added thereto, and then the sealed tube was evacuated with nitrogen three times. Subsequently, 2 mL of ultra-dry N,N-dimethylformamide was added to each sealed tube; the mixture was stirred at 50°C for 12 hours;

[0039] (3) The reaction was then quenched with a saturated aqueous ammonium chloride solution, and extracted with water and ethyl acetate; the extract was washed with a saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate, and then the extract was removed by rotary evaporation. The crude product was purified by silica gel column chromatography. The column chromatography separation conditions were: the stationary phase was 200-300 mesh silica gel powder, and the mobile phase was petroleum ether. Finally, 87.4 mg of the target product was obtained. The compound has the structural formula:

[0040]

[0041] The above target products were characterized, such as Figure 1 and 2 As shown, the result is: white solid; 1 H NMR (400MHz, CDCl3): δ7.39-7.24(m,9H),7.24-7.18(m,1H),4.15(s,2H)ppm. 13CNMR (100MHz, CDCl3): δ137.4,136.3,129.8,128.8(2C),128.4,127.1,126.3,39.0ppm.IR(KBr,neat):ν=1586,1480,1437,1090,1069,730,715,693cm -1 .HRMS(m / z):calcd for C 13 H 13 S[M+H] + 201.0738, found: 201.0737.

[0042] According to the characterization data, the obtained reaction product is benzyl (phenyl) sulfane; the product yield is calculated to be 87%.

[0043] Example 2

[0044] (1) Place the sealed tube equipped with a magnetic stirrer in an oven and dry for one hour. Take it out and plug it with a rubber stopper while it is still hot and insert a nitrogen balloon.

[0045] (2) Dimethyl (4-methylbenzyl) sulfonium trifluoromethanesulfonate (158.2 mg, 0.5 mmol, 1 equiv.), S-phenylbenzenesulfonylthioate (250.3 mg, 1 mmol, 2 equiv.), and zinc powder (65.4 mg, 1 mmol, 2 equiv.) were added to the sealed tube, and then the sealed tube was evacuated with nitrogen three times. Subsequently, 2 mL of ultra-dry N,N-dimethylformamide was added to each sealed tube; the mixture was stirred at 80°C for 12 hours;

[0046] (3) The reaction was then quenched with a saturated aqueous ammonium chloride solution, and extracted with water and ethyl acetate; the extract was washed with a saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate, and then the extract was removed by rotary evaporation. The crude product was purified by silica gel column chromatography. The column chromatography separation conditions were: the stationary phase was 200-300 mesh silica gel powder, and the mobile phase was petroleum ether. Finally, 100.9 mg of the target product was obtained. The compound has the structural formula:

[0047]

[0048] The above target products were characterized, such as Figure 3 and 4 As shown, the result is: white solid; 1H NMR (400MHz, CDCl3): δ7.37-7.33(m,2H),7.31-7.25(m,2H),7.25-7.18(m,3H),7.13(d,J=7.8Hz,2H),4.13(s,2H),2.35(s,3H)ppm. 13 C NMR (100MHz, CDCl3): δ136.7,136.6,134.2,129.4,129.1,128.7,128.6,126.1 ,38.5,21.1ppm.IR(KBr,neat):ν=1583,1511,1479,1436,1089,822,738,691cm -1 .HRMS(m / z):calcd for C 14 H 15 S [M+H] + 215.0889,found:215.0884.

[0049] According to the characterization data, the obtained reaction product is (4-methylbenzyl)(phenyl)sulfane; the product yield is calculated to be 94%.

[0050] Example 3

[0051] (1) Place the sealed tube equipped with a magnetic stirrer in an oven and dry for one hour. Take it out and plug it with a rubber stopper while it is still hot and insert a nitrogen balloon.

[0052] (2) After the mixture cools to room temperature, benzyl dimethylsulfonium trifluoromethanesulfonate (151.2 mg, 0.5 mmol, 1 equiv.), S-(4-(tert-butyl)phenyl)benzenesulfonylthioester (306.4 mg, 1 mmol, 2 equiv.), and zinc powder (65.4 mg, 1 mmol, 2 equiv.) are added thereto, and then the sealed tube is evacuated with nitrogen three times. Subsequently, 2 mL of ultra-dry N,N-dimethylformamide is added to each sealed tube; the mixture is stirred at 50°C for 12 hours;

[0053] (3) The reaction was then quenched with a saturated aqueous ammonium chloride solution, and extracted with water and ethyl acetate; the extract was washed with a saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate, and then the extract was removed by rotary evaporation. The crude product was purified by silica gel column chromatography. The column chromatography separation conditions were: the stationary phase was 200-300 mesh silica gel powder, and the mobile phase was petroleum ether / ethyl acetate 20:1. Finally, 107.4 mg of the target product was obtained. The structural formula of the compound is:

[0054]

[0055] The above target products were characterized, such as Figure 5 and 6As shown, the result is: colorless oil; 1 H NMR (400MHz, CDCl3): δ7.38-7.28(m,9H),4.15(s,2H),1.35(s,9H)ppm. 13 C NMR (100MHz, CDCl3): δ149.5,137.6,132.8,129.6,128.8,128.4,127.1,125.8,39 .2,34.4,31.2ppm.IR(KBr,neat):ν=2962,1495,1453,1362,1269,1121,826,697cm -1 .HRMS(m / z):calcd for C 17 H 21 S[M+H] + 257.1358, found:257.1354.

[0056] According to the characterization data, the obtained reaction product is benzyl(4-(tert-butyl)phenyl)sulfane; the product yield is calculated to be 84%.

[0057] Example 4

[0058] Example 4 is basically the same as Example 1, except that the metals in step (2) are different, as shown in Table 1 below:

[0059] Table 1

[0060]

[0061]

[0062] It can be seen from Table 1 that the reaction cannot proceed without adding metals; under the same reaction conditions, the reaction of different metals, such as manganese, iron, copper, aluminum, bismuth, indium, and magnesium, is almost impossible; while tin, lead, and zinc can be successfully synthesized, with zinc having the best effect and the highest yield of 81%.

[0063] Example 5

[0064] Example 5 is basically the same as Example 1, except that the solvent in step (2) is different, as shown in Table 2 below:

[0065] Table 2

[0066] Solvent Yield (%) Tetrahydrofuran 66 Dimethyl sulfoxide 74 N-Methylpyrrolidone 61 1,4-Dioxane 0 N,N-Dimethylformamide 81 N,N-Dimethylacetamide 77 Acetonitrile 0 Toluene 0 water 0

[0067] It can be seen from Table 2 that under the same reaction conditions, the reaction can hardly proceed for different solvents, such as 1,4-dioxane, acetonitrile, toluene, and water; while tetrahydrofuran, dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide can all be successfully synthesized, with N,N-dimethylformamide having the best effect, with the highest yield of 81%.

[0068] Example 6

[0069] Example 6 is basically the same as Example 1, except that the reaction temperature in step (2) is different, as shown in Table 3 below:

[0070] Table 3

[0071] temperature Yield (%) 25℃ 41 50℃ 81

[0072] It can be seen from Table 3 that under the same reaction conditions, different reaction temperatures, such as 25°C and 50°C, can all be successfully synthesized, with 50°C having the best effect, with the highest yield of 81%.

[0073] Example 7

[0074] Example 7 is basically the same as Example 1, except that the reaction time in step (2) is different, as shown in Table 4 below:

[0075] Table 4

[0076] Reaction time Yield (%) 6h 72 12h 81

[0077] It can be seen from Table 5 that different reaction times, such as 6 h and 12 h, can all be successfully synthesized, and the best effect is achieved when the reaction time is 12 h, with the highest yield of 81%.

[0078] Example 8

[0079] Example 8 is basically the same as Example 1, except that in step (2), the benzyl sulfonium salt and the thiosulfonate are different, as shown in Table 5 below:

[0080] Table 5

[0081]

[0082]

[0083]

[0084]

[0085] The present invention provides a direct cross-coupling reaction of benzyl sulfonium salt and thiosulfonate without transition metal catalysis, which not only uses benzyl sulfonium salt that is easy to synthesize as a coupling substrate, but also uses thiosulfonate as a substitute for thiol, avoiding the dangers such as odor during operation, and benzyl sulfonium salt can be stored at room temperature, showing excellent thermodynamic stability, and compared with other electrophilic reagents, they are also very safe and easy to prepare. The preparation method of the present invention has mild reaction conditions, simple post-processing, green steps, low pollution, high economic benefits, etc.

[0086] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A direct cross-coupling method of a benzyl sulfonium salt and a thiosulfonate, characterized in that: include, The benzyl sulfonium salt of formula I and the thiosulfonate of formula II are reacted in a solvent under the action of a metal to obtain a compound of formula III; wherein Ar comprises one of a phenyl substituent, a 4-methylphenyl substituent, a 2,4,6-trimethylphenyl substituent, a 4-tert-butylphenyl substituent, a 3,4,5-trimethoxyphenyl substituent, a 4-methoxyphenyl substituent, a 1,3-benzodioxolyl substituent, a 4-trifluoromethylphenyl substituent, a 4-trifluoromethoxyphenyl substituent, a 4-formylphenyl substituent, a 4-cyanophenyl substituent, a 4-fluorophenyl substituent, a 4-phenylphenyl substituent, and a 2-naphthyl substituent; R includes one of a phenyl substituent, a p-methylbenzene substituent, a p-tert-butylbenzene substituent, a p-methoxybenzene substituent, a p-(trifluoromethyl)benzene substituent, a 4-fluorophenyl substituent, a 4-chlorophenyl substituent, a 2-pyridine substituent, a 2-methylfuranyl group, a benzothiazole substituent, a 2-naphthyl substituent, and a benzyl substituent.

2. The direct cross-coupling method of benzyl sulfonium salt and thiosulfonate according to claim 1, characterized in that: The molar ratio of the benzyl sulfonium salt to the thiosulfonate is 1:

2.

3. The direct cross-coupling method of benzyl sulfonium salt and thiosulfonate according to claim 1 or 2, characterized in that: The metal is selected from one of tin, lead and zinc.

4. The direct cross-coupling method of benzyl sulfonium salt and thiosulfonate according to claim 3, characterized in that: The metal is zinc; the molar ratio of the metal to the benzyl sulfonium salt is 2:

1.

5. The direct cross-coupling method of a benzyl sulfonium salt and a thiosulfonate as claimed in any one of claims 1, 2 and 4, characterized in that: The solvent is selected from one of tetrahydrofuran, dimethyl sulfoxide, N-methylpyrrolidone, N,N-dimethylformamide and N,N-dimethylacetamide.

6. The direct cross-coupling method of benzyl sulfonium salt and thiosulfonate according to claim 5, characterized in that: The solvent is N,N-dimethylformamide.

7. The direct cross-coupling method of a benzyl sulfonium salt and a thiosulfonate as described in any one of claims 1, 2, 4, and 6, characterized in that: The reaction temperature is 25-50°C.

8. The direct cross-coupling method of a benzyl sulfonium salt and a thiosulfonate as described in any one of claims 1, 2, 4, and 6, characterized in that: The reaction time is 6 to 12 hours.

9. The direct cross-coupling method of a benzyl sulfonium salt and a thiosulfonate as described in any one of claims 1, 2, 4, and 6, characterized in that: The benzylsulfonium salt is selected from dimethylbenzylsulfonium trifluoromethanesulfonate, dimethyl (4-methylbenzyl)sulfonium trifluoromethanesulfonate, dimethyl (2,4,6-trimethylbenzyl)sulfonium trifluoromethanesulfonate, (4-(tert-butyl)benzyl)dimethylsulfonium trifluoromethanesulfonate, dimethyl (3,4,5-trimethoxybenzyl)sulfonium trifluoromethanesulfonate, dimethyl (4-methoxybenzyl)sulfonium trifluoromethanesulfonate, dimethyl (benzo [d] [1,3] dioxol-5-ylmethyl)sulfonium trifluoromethanesulfonate The invention is one of dimethyl (4-(trifluoromethyl) benzyl) sulfonium trifluoromethanesulfonate, dimethyl (4-(trifluoromethoxy) benzyl) sulfonium trifluoromethanesulfonate, dimethyl (4-(methoxycarbonyl) benzyl) sulfonium trifluoromethanesulfonate, dimethyl (4-(cyano) benzyl) sulfonium trifluoromethanesulfonate, dimethyl (4-(fluorobenzyl) sulfonium trifluoromethanesulfonate, dimethyl ([1,1'-biphenyl]-4-ylmethyl) sulfonium trifluoromethanesulfonate, and dimethyl (naphthalen-2-ylmethyl) sulfonium trifluoromethanesulfonate.

10. The direct cross-coupling method of a benzyl sulfonium salt and a thiosulfonate according to any one of claims 1, 2, 4, and 6, characterized in that: The thiosulfonate is selected from one of S-phenylbenzenesulfonylthioester, S-(p-tolyl)benzenesulfonyl sulfate, S-(4-(tert-butyl)phenyl)benzenesulfonylthioester, S-(4-methoxyphenyl)benzenesulfonylthioester, S-(4-(trifluoromethyl)phenylbenzenesulfonyl sulfate, S-(4-fluorophenyl)benzenesulfonylthioester, S-(4-chlorophenyl)benzenesulfonylthioester, S-(pyridin-2-yl)benzenesulfonylthioester, S-(2-methylfuran-3-yl)benzenesulfonylmethylsulfate, S-(benzo[d]thiazol-2-yl)benzenesulfonylthioester, S-(naphthalene-2-yl)benzenesulfonyl sulfate, and S-benzylbenzenesulfonyl sulfate.

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